Surprising health benefits to diverse grazing
Researchers at Lincoln University have found that offering a smorgasbord of diverse grazing has benefits for animals and farmers, as well as follow-on health benefits for people who consume meat from the animals.
Professor Pablo Gregorini and and post graduate researcher Dr Anita Fleming discovered a clear link between a new grazing management approach for cattle and significant health benefits for humans.
The pair found that cattle allowed to choose their own diet by grazing from a selection of five separate strips of monoculture plant species gained weight faster and had a better meat colour than cows on conventional ryegrass-based pasture, red clover pasture or cattle grazing a complex multispecies mixture.
The cows were allowed to selectively graze on strips of rye grass, lucerne, red clover, plantain and chickory for about 90 days.
The researchers then tested the blood of people who consumed meat from the cattle in the form of beef patties over a six-week period.
“The results were compelling. Our health reflects the way we graze our animals,” said Gregorini.
Blood samples taken from the trial participants who ate the beef showed an increase in vitamin E, which acts as a potent antioxidant and anti-inflammatory.
The samples also had higher levels of enzymes and aminoacids that lower total cholesterol and help build muscle and tissue and keep blood vessels open, he said.
Our research demonstrates the beneficial human health outcomes of eating higher-welfare food products.
“It’s not enough simply to say, we are what we eat. In fact, we are what we eat eats."
Gregorini said this was the first study of its kind that looks at the cause and effect of food.
The study effectively says if you eat this, it will be reflected in your blood an din your health.
"If you eat better your health will be better," he said.
Fleming said a relatively modest on-farm investment could give farmers productivity gains and meet a growing demand for healthy and ethical food production.
“Our research shows that by simply planting pasture in monoculture strips of common plant species that are already widely available, and allowing the animals to graze freely - to have ‘functional choice’ - farmers will not only enhance the welfare of their stock, including increased weight gain rates, but will also realise greater value from their product.
“More than ever, domestic and international consumers are demanding food products that are healthy and ethically and sustainably grown."
The grazing system would give farmers the competitive advantage of marketing a product that promotes human health and enhances animal welfare while at the same time safeguarding the environment, she said.
The Lincoln research team have also conducted trials with dairy cows, sheep and deer using a diverse strip grazing system and found similar results in animal performance, environmental impact and welfare including a reduction in nitrogen excretion.
A human trial with the test subjects eating lamb has recently finished with the results still pending but Gregorini expects similar "or even better" results than the beef study.
The performance of lambs on the strip-feed system was 22% better than on other grasses, he said.
For milk on strip-grazed dairy cows the improvement was between 8 - 10%.
The world-first study was funded by Lincoln University's Centre of Excellence,, Silver Fern Farms and Fertilizer New Zealand.
Gregorini hopes to source funding for human trials with milk and venison from animals on the strip pasture system. The venison would be of particular interest as the deer feeding off strip pastures had higher differences in metabolites that related to better brain development in foetuses, as well as the reduction of cancer and diabetes.
by Sharon Davis